diff --git a/pkgs/by-name/fl/flex-launcher/package.nix b/pkgs/by-name/fl/flex-launcher/package.nix
index de73d4b4480e..da5906e6278a 100644
--- a/pkgs/by-name/fl/flex-launcher/package.nix
+++ b/pkgs/by-name/fl/flex-launcher/package.nix
@@ -4,6 +4,7 @@
   SDL2,
   SDL2_ttf,
   SDL2_image,
+  libX11,
   cmake,
   validatePkgConfig,
   inih,
@@ -31,6 +32,7 @@ stdenv.mkDerivation (finalAttrs: {
     SDL2
     SDL2_ttf
     SDL2_image
+    libX11
     inih
   ];